Information processing apparatus and pedestrian navigation system using the same

ABSTRACT

A route computation apparatus having pedestrian-oriented map information for pedestrian route guidance, a portable route guidance apparatus, and markers located in an installation. A medium translation function is also included for translating input information of a given medium to information of another medium for output depending on current status of a pedestrian, whereby the information of interest is translated into information in a format suitable for the state in which the pedestrian is utilizing the portable apparatus.

TECHNICAL FIELD

The present invention relates to techniques for supporting pedestrianson the move with information. More particularly, the invention relatesto a pedestrian navigation system for navigating pedestrians bysupplying them with information about their positions andposition-related information.

BACKGROUND ART

Conventional systems for transmitting information to pedestrians includemobile telephones, portable computers, portable informationcommunication systems linking a mobile telephone and a portablecomputer, and car navigation systems used in a detachable manner asroute guidance systems for pedestrians or motorcycle riders. Informationis made available in multimedia forms. These systems are ushering in anera where users can obtain desired multimedia information anytime,anywhere.

The basic assumption for such systems is that users on the move come toa stop when performing necessary manipulations to exchange information;information cannot be sent or received by users who are still on themove or at work. Transmitted information is received and reproduced withits attributes (images, text, patterns, voice, etc.) unmodified (i.e.,image-attribute information is received as images, text information astext, pattern information as patterns, voice information as voice). Theattribute-bound nature of reproduction has made it difficult fortraveling or working users of the system to send or receive informationadequately. The system also has had difficulty in effectivelytransmitting information to visually, auditorily or otherwise disabledusers.

Route guidance systems based on transmitted information utilize the typeof information employed by car navigation systems. For that reason,pedestrians using such systems have not received information detailedenough to navigate them through, say, the interior of a building.

DISCLOSURE OF INVENTION

According to the invention, transmitted information based on any givenmedium is translated into the medium format best suited for the systemuser's mode of activity at the moment. For example, information based ondiverse media is translated into voice to let pedestrian users makebetter use of the translated information. Visually disabled users may beoffered not only voice-attribute information but also information basedon other media which is translated into a format suitable for thesituation where the information is received. Such a medium translationfunction is implemented by use of a facility for dispatching on areal-time basis real-time medium recognition functions and real-timemedium composition functions in accordance with the user's mode ofactivity at the transmitting or receiving side.

Detailed route guidance is implemented by installing at street cornersand inside buildings information transmitters for transmittingelectronically coded directional information as well as attributeinformation at least about the locations involved (name of a givenbuilding, its entrance, reception desk, elevators, etc.). Thetransmitted information is received by a telecommunication terminal heldby each user. Based on field intensities and other parameters, theterminal computes the distance to a target location. By matching thecomputed information with route information stored inside, the terminalprovides the user with route guidance not only outdoors but also insidea given building.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view outlining a configuration of a systemembodying the invention.

FIG. 2 is a block diagram showing a system configuration of a stationaryroute computation apparatus equipped with a communication function.

FIG. 3 is a block diagram depicting a system configuration of a portableroute guidance apparatus equipped with communication and positiondirection finding functions.

FIG. 4 is a block diagram of an installation marker equipped with acommunication function.

FIG. 5 is a schematic view showing how route guidance is providedconventionally.

FIG. 6 is a schematic view illustrating how route guidance is providedaccording to the invention.

FIG. 7 is a map outlining the inside of an installation.

FIG. 8 is a schematic view showing how an installation marker ismounted.

FIG. 9 is a side view depicting how an installation marker is typicallymounted.

FIG. 10 is a plan view illustrating how an installation marker ismounted.

FIG. 11 is an external view of a communication function-equippedstationary route computation apparatus.

FIG. 12 is a schematic view showing situations in which informationbased on some media cannot be transmitted.

FIG. 13 is a schematic view sketching how information is translatedbetween media.

FIG. 14 is a schematic view indicating how information is translatedfrom one medium to another.

FIG. 15 is a block diagram of an information processing apparatusembodying the invention.

FIG. 16 are tabular views listing parameters of a road map and aninstallation map.

FIG. 17 is a tabular view listing parameters of a route map.

FIG. 18 is a flowchart of steps representing Dijkstra's method.

FIG. 19 is a block diagram of a modified portable route guidanceapparatus for use both on a car and by a pedestrian.

FIG. 20 is a flowchart of steps for analyzing route statements.

FIG. 21 is a flowchart of steps for extracting word candidates.

FIG. 22 is a flowchart of steps for matching keywords.

FIG. 23 is a flowchart of steps for generating a word string.

FIG. 24 is a set of views showing a route guidance statement, keywords,analyzed results of a route statement, and patterning.

FIG. 25 is a flowchart of steps constituting a drawing process.

FIG. 26 is a schematic view showing a pattern drawing example.

FIG. 27 is a schematic view showing another pattern drawing example.

FIG. 28 is a schematic view showing another pattern drawing example.

FIG. 29 is a schematic view showing another pattern drawing example.

FIG. 30 is a schematic view showing another pattern drawing example.

FIG. 31 is a table of correspondence between sensor outputs on the onehand and information media subject to translation on the other hand.

FIG. 32 is a schematic view depicting a structure of an optical sensor.

FIG. 33 is a schematic view indicating a structure of an accelerationsensor arrangement.

FIG. 34 is a schematic view sketching a structure of a sound volumesensor.

FIG. 35 is a flowchart of steps constituting a process performed by auser activity recognition processing part.

FIG. 36 is a flowchart of steps constituting a process carried out by amedium translation control processing part.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a configuration of a system embodying the invention. Thesystem comprises a stationary route computation and informationproviding apparatus 1 equipped with a communication function (called theinformation providing apparatus 1 hereunder), a portable route guidanceapparatus 2 equipped with communication and direction finding functions(called the route guidance apparatus hereunder), and a stationaryinstallation marker 3 equipped with a communication function (called themarker hereunder). In operation, a user (pedestrian) carries the routeguidance apparatus 2 around. When the pedestrian sends his or hercurrent position and an intended destination through the route guidanceapparatus 2 to the information providing apparatus 1, the apparatus 1computes an appropriate route using necessary databases (maps, etc.) andsends the computed route information back to the route guidanceapparatus 2. The pedestrian then moves toward the destination byfollowing the transmitted route information presented by the routeguidance apparatus 2. On his way to the destination, the pedestrian mayreceive on his route guidance apparatus 2 information from markers 3mounted at an entrance to a building, at its elevator, and at otherlocations of the installation of interest. The marker-originatedinformation helps provide the pedestrian with detailed route guidance.

FIG. 2 depicts a system configuration of the information providingapparatus 1 according to the invention. The information providingapparatus 1 comprises a route computing part 11 for acquiring a suitableroute using pedestrian-oriented databases (e.g., a digital road mapdatabase 15 for pedestrians, an installation map database 16 containinginformation about structures and stores inside buildings, a transportnetwork and timetable database 17 about public transportation, and aroad repair and traffic control database 18 as well as a trafficaccident and obstruction database 19 containing information aboutobstacles to pedestrian movements) and in response to requests from theuser (current position, intended destination, etc.). The informationproviding apparatus 1 also includes: an information selecting part 12for selecting necessary information in response to a request forinstallation guidance information; a guidance information generatingpart 13 for generating necessary guidance information by puttingtogether information obtained by the route computing part 11 andinformation selecting part 12; and a communicating part 14 forcommunicating with the route guidance apparatus 2 carried by the user.

FIG. 3 sketches a system configuration of the route guidance apparatus 2according to the invention. The route guidance apparatus 2 is driven bybatteries and comprises: a communicating part 201 for communicating withthe information providing apparatus 1 and markers 3; a communicationdata storing part 202 for recording communication data for storage; aninformation navigation part 203 for generating not only communicationinformation to be sent to the information providing apparatus 1 but alsoguidance information destined for pedestrians based on the routeinformation from the apparatus 1, on current position information from acurrent position and advancing direction measuring part 211 (directioninformation supplied from a direction sensor 208, current position fedfrom a GPS receiver 209), and on installation marker directioninformation from an emitter direction and distance measuring part 212(connected to a beam receiver 210 receiving installation ID and beamemission direction information from the marker 3); a user activityrecognizing part 207 for recognizing the user's walking activity(whether the route guidance apparatus 2 is held by hand or placed in abag; whether the pedestrian is walking, running or at rest) by resortingto an optical sensor 205 mounted on a side of the route guidanceapparatus 2 or to a walking sensor 206 constituted by accelerationsensors or the like; a medium translation controlling part 204 whichtranslates user-originated information of a given medium into a mediumformat accessible by the information navigation part 203 in keeping withthe output from the user activity recognizing part 207, and whichtranslates guidance information from the information navigation part 203into a medium format accessible by the user; and a group of I/O devicesconnected to the medium translation controlling part 204 (e.g., display213, speaker 214, vibrator 215, microphone 216, tablet 217, keyboard218).

FIG. 11 is an external view of the route guidance apparatus 2. Theapparatus 2 is made up of a flat display 213 overlaid with atouch-sensitive panel, a GPS antenna 209, a beam receiver 210, acommunication antenna 201, a speaker 214 and a microphone 216. The GPSantenna 209 and communication antenna 201 can become unstable inoperation upon interfering with each other depending on the frequenciesof radio waves being used. The potential trouble is averted by mountingthe two antennas well apart as illustrated, or by setting up a commonantenna for receiving signals that may be suitably separated inside.

FIG. 4 depicts a system configuration of the marker 3 according to theinvention. The marker 3 comprises: at least a set of angle informationmultiplexing parts 34, 35 and 36 which store installation informationand which are connected to an information generating part 37 foroutputting information; and beam emitters 31, 32 and 33 connectedrespectively to the angle information multiplexing parts 34, 35 and 36.A communicating part 38 may be provided for connection to an externalinformation controlling apparatus whereby modification of installationinformation from the information generating part 37 is facilitated. Ifthe beam emitters are designed to use optical beams, each beam emittermay illustratively utilize a lens system to restrict its range of beamemission. Beam angles may be determined illustratively on a 360-degreedirection gauging arrangement, graduated clockwise with reference to themap direction of the north being set as zero. Where beams carry suchangle information, the route guidance apparatus 2 receiving a given beamcan readily determine the direction in which to guide the user. Themarkers 3 are furnished at an entrance to a building, at staircasesinside, at an elevator, at the reception desk and other strategic pointsof the interior for route guidance. As shown in FIG. 8, a marker 3 ismounted illustratively above the reception desk as a beam emitter foremitting beams in three directions. FIG. 9 is a side view depicting howthe marker is mounted, and FIG. 10 illustrates the mounting of themarker as viewed from above. Desired beam patterns are obtained by asuitable lens system if the beam emitter uses an optical beam or by anappropriate antenna arrangement if the beam emitter employs radio waves.

Described below with reference to FIGS. 5 through 7, FIGS. 16 through 18is a procedure for computing the route from a starting point (FIGS. 5and 6) to a goal (e.g., second exhibition room on the third floor of ∘∘∘Museum). Traditionally, route guidance has been targeted mainly forvehicles. Where a destination is established for such vehicular routeguidance, the routing takes place along roads. An actual system mayguide the user up to the road closest to the goal as shown in FIG. 5. Anavigation system used by a pedestrian, on the other hand, is requiredto guide the user into the target building as depicted in FIG. 6. Therequirement is met by provision of installation maps such as those shownin FIG. 7. Because outdoor-use positioning devices represented by GPScannot be used inside buildings, guidance in the building interiorrequires setting up direction emitters such as markers 3 at strategiclocations inside the installation. FIG. 16 lists typical databaserecords of a road map and an installation map. In addition totraditional indications of crossings (C1, C2, C3, C4, etc.), FIG. 16(a)includes accessibility information for pedestrians and links to markerslocated at entrances to installations such as buildings. Besides thecrossing locations, FIG. 16(b) includes positions of markers inside theinstallations, beam emission directions, and link information (IDs ofadjacent markers).

Where route computations are carried out by use of the road andinstallation maps shown in FIG. 16, a procedure for routing along roadsis separated from a procedure for routing inside installations. For theroad routing, a road-bound goal is established at a mediating location“m” on the road. If the ultimate goal is located inside an installation,the ID of an adjacent road point is obtained from the link informationin the installation map. In computation, the route along the roads(i.e., from the starting point through C1, C3, C4 and m) is firstacquired, followed by the route inside the installation (passing throughm, mh, mf1, me, mf3 and mf3 r 2).

FIG. 18 is a flowchart of steps constituting Dijkstra's algorithm, arepresentative algorithm for route computation. Using the starting pointas its initial value, the algorithm obtains minimum appraised valuessuch as distances from one point to the next (nodes) until a goal isreached. Eventually a route represented by the minimum appraised valuesfrom the starting point to the goal is obtained. If a route inside amultiple-story installation needs to be acquired, as in the currentexample of the invention, there is no need to compute routing on allfloors. That is, the computing time is reduced by searching through onlythe map of the floor where the goal is located.

FIG. 17 is table that lists results of route computations in thisexample. In terms of route information, the table includes ID names ofmediating locations, positions of the mediating locations, approachangles to the mediating locations, and departure angles from themediating locations. The two kinds of angle information are provided tohelp obtain the correct advancing direction, allowing for pedestrians'general tendency to change their bearings in an extremely erraticfashion, e.g., looking sideways and backwards while walking.

On the basis of the route information listed in FIG. 17, the routeguidance apparatus 2 carried by the user guides him or her from thestarting point to the goal. While operating outdoors, the apparatus 2compares the route information with the current position and advancingdirection derived from GPS. Once inside an installation (e.g., ∘∘∘Museum), the route guidance apparatus 2 cannot resort to GPS and reliesinstead on beams received from emitters for continuous guidance. Thereceived beams reveal angle information which is translated into thedirection, while the current position is acquired by measuring theintensity of the beams. Such a guidance method based on GPS and beamemissions may be applied illustratively to a system for guiding avehicle from the streets into an underground parking lot. The method isalso applicable to a system for physical distribution at portfacilities, guiding containers from container yards to appropriatelocations in the holds.

An information translation function will now be described with referenceto FIGS. 12 through 15. Today's information services are offeredtypically in a multimedia format. That is, sets of information areexpressed using multiple media such as characters, patterns, images andvoice. Of these types of information being offered, visual informationcannot be fully utilized by people at work (e.g., while walking)because, as shown in FIG. 12, their attempts to make use of suchinformation could lead to an accident. In a crowded situation (e.g., ameeting), voice information can disturb people near the person receivingit. Such impediments to information availability also apply to visuallydisabled people being presented with visual information or to auditorilydisabled people being offered voice information.

In such cases, as illustrated in FIG. 13, the medium translationfunction translates the information of interest into information with anattribute accessible by the pedestrian (user) on the basis of the actualor judged state of activity of the pedestrian (user).

Basically, the medium translation function involves translatinginformation of a given medium A into text by use of recognitiontechniques and reproducing information of a target medium usingcomposition techniques, as shown in FIG. 14. Because the inventiveapparatus determines into which medium to translate information of agiven medium in accordance with the state of the pedestrian (user), theapparatus is illustratively constituted as shown in FIG. 15.Specifically, the constitution of FIG. 15 is acquired by supplementingthe setup of FIG. 14 with a medium translation table that defines intowhich medium input information of a given medium is to be translated.The constitution primarily comprises: a multimedia information receivingpart 151 for receiving multimedia information and the like; a mediumtranslation module 152 (or information translating part) for translatingthe information received by the multimedia information receiving part151; and a multimedia information outputting part 153 for outputtinginformation translated by the medium translation module 152. The mediumtranslation module is made up of a use status detecting part 154 fordetecting the use status of the user utilizing the apparatus; a usestatus judging part 155 for judging the use status of the user on thebasis of detected results from the use status detecting part 154 and inaccordance with a medium translation table 157 defining beforehand whichdetected values from the use status detecting part 154 correspond towhich user status; and an information translating part 156 fortranslating information received by the multimedia information receivingpart 151 in a manner relevant to the judgment by the use status judgingpart 155. The use status detecting part 154 may be implementedillustratively in the form of an optical sensor, acceleration sensors, asound volume sensor that measures the volume of sound picked up bymicrophones, or a temperature sensor. The medium translation table 157may be established illustratively by sensors (205 and 206 in FIG. 3)which as a portion of the use status detecting part 154 obtain theuser's status of activity, or by the pedestrian (user) issuing explicitsettings (through menus, etc.). For example, if the optical sensordetects a low level of light (at a dark location), the apparatus isjudged to be currently placed in a bag or the like. In that case, theinformation of interest is output by voice through earphones or thelike. If the optical sensor detects a high level of light (at awell-lighted location) and if, say, acceleration sensors detect astationary state through vibration analysis, the user is judged to becarrying the route guidance apparatus 2 by hand. In such a case, imageinformation is provided unmodified. In this manner, the manner ofoffering information is changed automatically depending on the situationin which the information of interest is to be provided. If a microphonepicks up an appreciably high level of ambient noise, then voiceinformation indicating that location C3 is closed to traffic because ofroad repairs may be translated through voice recognition illustrativelyinto characters for visual display. The information may be furtheranalyzed and divided into “the location C3” on the one hand and “theclosed traffic situation” on the other hand, which may be turned into “aclosed traffic” indication on a road map through medium-to-mediumtranslation. When information of a given medium is translated by themedium translation function into information of at least one othermedium, desired information is offered to users with a minimum loss ofinformative ingredients regardless of the situation they find themselvesin at a given moment. This allows the users to be more efficient thanbefore in acquiring necessary information.

FIG. 19 is a partial block diagram of a modified portable route guidanceapparatus for dual use both on a car and by a pedestrian. In the setupof FIG. 19, a user activity recognizing part judges whether the user iswalking or driving a car, and sends the judgment to a communicatingpart. Depending on the user's state thus determined, the user activityrecognizing part causes the communicating part to select either adatabase for pedestrians or a database for vehicles and to acquiresuitable information therefrom. The setup allows the user to obtainroute information in each of his or her two possible states of activity.

Described below with reference to FIGS. 20 through 30 is how a route mapis generated illustratively from a route guidance statement.

The statement may be one in FIG. 24, specifying a route from “station A. . . to building B.” It is assumed here that the route guidancestatement “from station A to building B” is stored in advance as textinformation. The following processes are carried out to obtaineventually a route map such as one shown in FIG. 30.

Four steps shown in FIG. 20 are initially carried out to translate theroute guidance statement in question into a string of words destined forpatterning.

In the first step, word candidates are first extracted from the routeguidance statement, as shown in FIG. 21. Extraction of each word is madeeasier illustratively by picking up characters of the same type.

In the second step, as depicted in FIG. 22, each of the word candidatesis compared with keys (“KEYS” in FIG. 24). When a word candidate ismatched with a key, the attribute (position, direction, route, distance,etc.) of the key is attached to the word candidate in question.

In the third step, as indicated in FIG. 23, the words are rearranged interms of a starting point, directions, routes, and distances up to thedestination, in that order, with emphasis on word consistency and logic(“PATTERNING” in FIG. 24).

In the fourth step, the word strings above are patterned in the stepsshown in FIG. 25.

First, the orientation and an approximate scale of a map to be drawn areestablished (step 25-1). The initial starting point is set in amediating location buffer (step 25-2). This mediating location is setclose to the center of the map screen (step 25-3). In this state, aninitial screen for the map to be drawn is set in a display memory.Thereafter, steps 25-4 through 25-13 below will be repeated until themediating location coincides with the destination.

Station A is first extracted as the starting point from among the wordstrings for patterning (step 25-4). The location is written to thedisplay memory in the form of a predetermined symbol or a pattern asshown in FIG. 27 (step 25-5). The direction (north), route (main street)and distance (300 m) are extracted. If a routing line is judged to becapable of being drawn on the screen on the initially established scale(step 25-9), then a vector of the set distance from the starting pointin the established direction and a name of the route are drawn (steps25-10, 25-11). This creates a drawing of FIG. 28 in the display memory.The next mediating location (crossing) is extracted (step 25-12). Step25-4 is then reached again for another pass of patterning. If thedrawing range is found in step 25-9 to exceed the settings, step 25-15is reached in which the scale is suitably modified. Illustratively, whenthe distance is acquired from the initial starting point to the tip ofthe vector, the scale may be set for double the ratio of the acquireddistance to the set distance. This creates drawings of FIGS. 29 and 30.The final pattern of the building B is drawn in step 25-14.

In the manner described above, a route map may be generated from a routeguidance statement. Route guidance statements are obtainedillustratively through kana-kanji translation with a keyboard, voicerecognition, handwritten character recognition, and off-line imagerecognition. The route guidance statements thus obtained may each beannounced through speech synthesis or drawn in patterns through theabove-described processing.

Where light intensity information from an optical sensor, motioninformation from acceleration sensors, and sound volume information frommicrophones are used to judge the status of the apparatus, theprocessing of status judgment by use of such activity sensors willbenefit from a classification table such as one shown in FIG. 31. Thetable, which defines into which medium to translate information of agiven medium in each of differently judged states, is retained in amemory area accessible by a user activity recognition processing part206.

FIGS. 32 through 34 schematically show structures of various sensors.FIG. 32 indicates a structure of the optical sensor. Output voltages ofthe sensor are subjected to analog-digital conversion (A/D conversion inFIG. 32) by use of a photo-transistor arrangement or the like. Theconverted voltages are retained in a buffer and retrieved as needed bythe user activity recognition processing part 206. If the optical sensoris mounted in parallel with a display surface, the output of the opticalsensor is generally increased while the user is watching the display. Inthat case, a “high” level of light intensity is recognized. If theapparatus is placed in a bag or the like, the output of the opticalsensor drops. Then a “low” level of light intensity is recognized.

FIG. 33 shows a structure of a three-axis acceleration sensorarrangement. Outputs of the individual sensors are subjected toanalog-digital conversion before being placed into buffers. The buffercontents are selected as needed by a selector and retrieved by the useractivity recognition processing part 206.

FIG. 34 outlines a structure of a microphone sensor. The microphoneoutput, which is generally in alternating-current form, is rectified bya rectifying circuit into direct-current form. The resulting DC valuesare subjected to analog-digital conversion before being placed into abuffer. As in the case of the above-mentioned sensors, the buffercontents are selected by a selector as needed and retrieved by the useractivity recognition processing part 206.

FIG. 35 shows a process flow of the user activity recognition processingpart 206. First, the sensor outputs are retrieved (steps 206-1 through206-3). The processing part 206 then references the classification tableto select the applicable state (step 206-4). An appropriate mode forinformation medium translation is selected and sent to the mediumtranslation controlling part 204.

FIG. 36 shows a process flow of the medium translation controlling part204. First, the information of interest is acquired (step 204-1). Acheck is made to see if the translation mode corresponding to theacquired information is other than a “no translation” mode (step 204-2).If translation is judged to be necessary, then the information istranslated into a target medium through a recognition process (step204-3). For example, if voice information needs to be translated intocharacter information, the information of interest is translated intocharacter strings through a voice recognition process. A characterrecognition process or an image recognition process is also utilized asneeded. Thereafter, a composition process is carried out for output(step 204-4). In this example, a procedure of translating the characterstrings into outline fonts corresponds to the composition process.Speech synthesis or pattern drawing is also employed as needed.

INDUSTRIAL APPLICABILITY

As described, the pedestrian navigation system according to theinvention provides a detailed route guidance service allowingpedestrians to reach a target location in a specific installation. Inaddition, the inventive system permits automatic changing of modes forinformation exchanges depending on the user's status of activity such aswalking, working, and participation in a meeting, whereby necessaryinformation is made available in a status-compatible format on asufficiently detailed basis.

What is claimed is:
 1. A pedestrian navigation system for transmittinginformation to a portable pedestrian guidance apparatus carried by apedestrian so that the portable pedestrian guidance apparatus outputsthe transmitted information to navigate said pedestrian, said pedestriannavigation system comprising: a plurality of markers mounted at variouslocations in an installation, wherein each marker outputs a beam whichcarries installation identification information for identifying alocation at which said marker is installed and direction informationindicating a direction at which said beam is being emitted by saidmarker; and a route computation information providing apparatus having adatabase for a pedestrian-oriented map including the locations of saidmarkers, a computation function for computing routes based on saidinstallation identification information and said direction information,and a communication function for communicating with said portablepedestrian guidance apparatus, wherein said portable pedestrian guidanceapparatus comprises: a communication function for communicating withsaid route computation information providing apparatus and said markers,and a position and direction measuring function for measuring a positionand direction based on said installation identification information andsaid direction information.
 2. A pedestrian navigation system accordingto claim 1, wherein said portable pedestrian guidance apparatus furthercomprises: an information translation function for translatinginformation sent either from said route computation informationproviding apparatus or from said markers into information in a formatapplicable to a use state of a user making use of said portablepedestrian guidance apparatus.
 3. A pedestrian navigation systemaccording to claim 2, wherein said information translation functioncomprises: a detecting part for detecting said use state of said usermaking use of said portable pedestrian guidance apparatus; a translationtable defining beforehand relations of correspondence between a detectedresult from said detecting part and said use state of said user; ajudging part for judging said use state of said user based on saiddetected result from said detecting part and on said translation table;and an information translating part for translating information receivedby said receiving part in accordance with a judged result from saidjudging part.